B
billgate_tl_nthai


CM:
[tex] \frac{a}{a+b} + \frac{b}{b+c} + \frac{c}{c+a} \leq \sqrt[]{\frac{a}{b+c}}+\sqrt[]{\frac{b}{c+a}} + \sqrt[]{\frac{c}{a+b}}[/tex]
Với a, b, c > 0
[tex] \frac{a}{a+b} + \frac{b}{b+c} + \frac{c}{c+a} \leq \sqrt[]{\frac{a}{b+c}}+\sqrt[]{\frac{b}{c+a}} + \sqrt[]{\frac{c}{a+b}}[/tex]
Với a, b, c > 0